1. Field of the Invention
The present invention generally relates to a semiconductor device, and more particularly to a vertical semiconductor device.
2. Description of Related Art
FIG. 1 shows a perspective view of a conventional semiconductor device 100, which includes, from bottom to top, a sapphire substrate 11, an n-type doped layer 12, an active layer 13, a p-type doped layer 14, a transparent contact layer 15, a negative electrode 16 and a positive electrode 17. A light emitting diode (LED) configured in accordance with the structure shown is called a horizontal LED because its current flows horizontally from the positive electrode 17 to the negative electrode 16. Current crowding ordinarily occurs under the negative electrode 16, and thus increases operating voltage, dynamic resistance, and temperature in the semiconductor device 100.
Accordingly, a need has thus arisen for a novel semiconductor device to overcome the current crowding and increased temperature.